The preparation of polymeric tri-substituted silylalkynes employing an organic solvent and a suitable catalyst such as TaCl.sub.5, MoCl.sub.5, NbCl.sub.5 or other Group VB or IVB metal halides is known, as is the formation of polymeric membranes and gas separation processes using the polymeric membranes.
The preparation of poly(trialkylsilylpropyne) and treated, semi-permeable polymeric membranes comprising a polymer having the general structural formula: ##STR1## wherein R.sub.1 is a linear or branched C.sub.1 -C.sub.4 alkyl group; R.sub.2 and R.sub.3 are independently linear or branched C.sub.1 -C.sub.6 alkyl groups; R.sub.4 is a linear or branched C.sub.1 -C.sub.12 alkyl group or aryl group; X is a C.sub.1 -C.sub.3 alkyl group or phenyl; m is at least 100 and n is 0 or 1, is disclosed in the Langsam U.S. Pat. No. 4,657,564. These polymers are prepared from tri-substituted (silylalkynes), the polymerization method therefore being incorporated herein by reference.
G.B. patent application No. 2,135,319A discloses the polymerization of one or more 1-monoalkyl (C.sub.1 -C.sub.12) dimethysilylpropynes using various silypropyne monomers in the presence of halides of transition metals of Group VB of the Periodic Table. Organo-aluminum compounds are described as co-catalysts.
The polymerization of 1-(trimethylsilyl)-1-propyne employing pentahalides of niobium and tantalum in a toluene solution at 80.degree. C. along with the effects of solvents and temperature are described in an article by T. Masuda, et al. entitled "Polymerization of l-(trimethylsilyl)-l-propyne by Halides of Niobium (V) and Tantalum (V) and Polymer Properties," Macromolecules Vol. 18, No. 5, pp. 841-845 (1985).
Molybdenum and other methyl halides are disclosed as catalysts for the polymerization of sterically hindered acetylenes and dialkyl-acetylenes in a solvent by T. Masuda, et al. in an article entitled, "Polymerization of Methylpentynes by Transition Metal Catalysts: Monomer Structure, Reactivity, and Polymer Properties" Polymer Journal, Vol. 4, No. 5, pp 371-377 (1982).
T. Masuda in an article entitled "Synthesis of High Polymers from Substituted Acetylenes: Exploitation of Molybdenum and Tungsten-Based Catalysts," Acc. Chem. Res., Vol 17, pp. 51-56 (1984) discloses the polymerization of aromatic and aliphatic acetylenes.
The present invention is based on the discovery that the addition of tertiary amines to a solution containing Group VB or VIB metal halide catalysts or mixtures thereof forms a very active binary catalyst system which accelerates the polymerization of tri-substituted sylalkynes, particularly trimethylsilypropyne, and increases the molecular weights of the resultant polymer beyond what would normally be expected by prior art processes.